Rotary well drilling bit control



March 14, 1933. J. H. HoLLEs'rELLE ROTARY WELL DRILLING 'BIT yCONTROL Filed May 2, 1928 2 Sheets-Sheet 1 March 14 1933.

Patented Mar. 14, 1933 UNITED STATES PATENT oF-Flce JAN H. HOLLESTELLE, OF ST. LOUIS, MISSOURI, ASSIGNOR TO THE KENNEDYE CORPO- RATION, OF ST. LOUIS, MISSOURI, .A CORPORATION OF DELAWARE ROTARY WELL DRILLING BIT CONTROL Application led Hay 2, 1928. Serial No. 274,454.

The present invention relates to improvements in a rotary welldrilling bit control, and refers more particularly to improvements applicable to conventional rotary well drilling equipment without substantial change in structure or function.

The ordinary rotary well drilling equipment comprises power equipment, a rotary table, a control hoist and mud pump, all placed at the surface of the ground and so arranged and connected that, when a drill pipe carrying a drill bit is placed in the rotary table, the drill pipe may be revolved by the rotary table and raised or lowered by the control hoist and water forced through the drill pipe and through the -drill bit by the mud pump.

With this arrangement as the depth of the hole increases, so does the length of the drill pipe carrying the drill bit, and as oil wells and the like are drilled to a depth of several thousand feet, and as the pressure against the drill bit for actual drillin must be transmitted to the drill bit throug the drill pipe by allowing it'to rest upon the drill bit, there is caused a great lateral deflection of the drill pipe that is only retarded by the sides of the hole in which the drill pipe is revolving, and there is noy means of knowing what pressure is being transmitted to the -drill bit for actual drilling, Such an arrangement providing for practically no control of the forces required to cause the drill bit to proceed in a plumb direction, or of any definite force against the drill bit for drilling operations,

' trusts entirely to luck and ideal formations for a straight hole.

Many of the faults of the present equipment may be eliminated by installing in the drill pipe the rotary drill bit control which forms the subject matter of the present invention. The use of the device of the present invention will practically eliminate from the drill pipe all lateral deflection and in addition perinit only a known portion and weight of the drill pipe to rest upon the drill bit during actual drilling.

Among the salient objects of the invention are to so form and construct a rotary well drilling bit control that the lines of forces operating the bit will transmit their energy in a direction and manner that will tend to produce a plumb hole; to eliminate practically all lateral deflection from the drill pipe originating from stresses produced in the pipe by having a long length of pipe continuously ]oined together from the surface of the ground to the drill bit, upon which the pipe directly rests during actual drilling operations; to have lonly a known portion and weight of the power transmitting drill pipe rest directly upon the drill bit during drilling operations; to automatically retard the sudden drop of the drill bit into an opening or soft formation, if such is encountered during drilling operations; to permit the drill bit to rise slowly from a hard formation, if caught therein during drilling, by an upward movement of only a portion of the power transmitting pipe; to drill a hole of more uniform cross section than now obtained; to reduce the power required for operating the drill; to promote efliciency in well drilling operations; and minimize' breakdowns and operating costs, and in general to provide -a simple andefficient device to accomplish the above objects.

Other objects, features and advantages of the present invention will be more apparent from the following description:

In the drawings, Fig. l is a vertical sectional view partly in elevation, of the entire device.

Fig. 2 is an elevational View,l partly f in vertical section, of the major parts of the device showing the extreme upward position of the drillbit control shaft.

Fig. 3 is an elevational view, partly in section, of part of the device showing the extreme downward position of the drill bit control shaft.

Fig. 4 is a transverse sectional view taken on line 4 4 of Fig. 1.

Fig. 5 is a transverse sectional view taken' on line 5-5 of Fig. 1.

Fig. 6 is a transverse sectional view taken on line 6-6 of Fig. 1.

Fig. 7 is a transverse sectional view taken on line 7-7 of Fig. 1.

Referring more in detail to the drawings,

vof the control shaft the pipes 1 and 2, which may take the form of conventional casing, secured together by the special coupling 3, and the casting or forging 4 secured to the lower end of the pipe 2 and provided with a bushing 5 provides the housing for holding and directing the operating parts of the device of the present inven` tion contained therein.

A tubular control shaft 5 may have attached to its upper end a tubular casting 6 whi'bh may be provided with packing ring 7, the arrangement being such that the casting. or forging 6 is adapted to move with shaft 5 within the pipe 1. Surrounding the tu- V bular control shaft 5 and adapted to move within a recess 8, may be mounted a tubular casting or forging 9 which rests, when at its extreme downward position, on the washer 10 supported by the shoulder 11. Apertures 12 in the tubular control shaft 5 connect the recess 8 with a recess 13.

The combination coupling and drive bushing 3 may be provided interiorly with one or more ribs 15 adapted to register with one or more complemental grooves 16 provided in the tubular control shaft 5 within the limits of the rings forming shoulders 11 and 17. The shoulder 17 may carry a packing ring 18 and may be secured to the tubular pipe 24 by one or more screws 20. The shoulder 17 maybe provided with apertures 21 and the coupling 3 may be similarly provided with apertures 23 to permit proper lubrication of the working parts and provide passageways between the recesses 22 and 13.

Recess 25, connected with recess 22 by the apertures 33, serves as a reservoir for oil, as do recesses 22, 13 and 8, and recess 25 is provided with a drain passageway closed with the removable plug 27. Recess 26 may contain the packing rings 28 and 29 adapted to the tubular shaft 24, which packing rings may be held securely in position by the bushing =5 and spring 30.

It will be noted that anti-friction rings 33 of suitable metal may be placed on the shoulders of the coupling 3 and within the recess 13 to reduce wear when the shoulder is resting on the rings, and anti-friction rings 34 of suitable metal may be placed on the shoulder of casting '4 and within recess 22 to similarly reduce friction when shoulder 17 rests thereon. The anti-friction rings 33 and 34 in Fig. 1 may be integral with castings 5 and 6, or may be made separately.

To the lower end of the tubular pipe 24 may be secured common drill pipe'31 by a conventional pipe coupling 32, and to the end of the drill pipe 31 is secured the drill bit holder and drill bit (not shown), or the lower end of tubular pipe 24 may be secured to special drill pipe such as seamless tubing with say, four inch wall thickness for the purpose of confining the weight to the smallest length of drill pipe or common drill pipe may be used by inserting a two inch tube inside of a six inch drill pipe or tube and the surrounding space filled with molten lead to increase the weight per lineal foot of drill pipe, thus making the portion of drill pipe which is free to move up and down with the bit control properly rigid so as not to permit the bit to readily drill off from the vertical when anti-clines or sinclines are encountered.

The drill pipe 31 between the coupling 32 and the drill bit holder, except for a passageway for water (which may be provided by inserting within the drill pipe 31 a pipe 32 of the proper size) may be filled with lead or the like 35, whereby to furnish the weight desired to rest upon the drill pipe. Or if it is not desired to weight the pipe, the length of the pipe 31 may be increased sufficiently to furnish the weight desired to rest upon the drill bit. For general use, the most efiicient weight on the drill bit has been ascertained to be approximately 10,000 pounds.

In the installation and operation of the device of the present invention, the device having been assembled, the recesses 13, 22 and are filled with a heavy lubricating oil or grease of such characteristics as to move slowly through the openings connecting the recesses 8 13, 22 and 25 when under pressure due to the movement upward or downward of the shafts 5 and 24.

The upper end of the pipe 1 is attached by the conventional pipe coupling to the drill pipe leading through the rotary drill table and connected with the control hoist, while the lower end of the shaft 24 is connected to a drill pipe of the weight desired to rest on the drill bit during actual drilling. With the control hoist, the device of the present invention is lowered into position for drilling and the drill bit is let down until it rests upon the formation to be cut and until the drill control shaft 5 is in its upward position as illustrated in F ig. 2, in which case the shoulder 17 will be in contact with the shoulder on the casting or forging 3.

The rotary table is then started, and as it revolves so will the drill pipe, control device and the drill bit. Since the weight of the pipe below' the control shaft 5 rests upon the drill bit, the latter will start cutting and proceed downwardly. Through its own weight, the control shaft, being provided with one or more grooves adapted to register with a complemental rib or ribs on the casting or forging 3, will also move downwardly. This downward movement will not take place suddenly due to the fact that the downward movement of the control shaft 5 is directly controlled by the speed with which the lubricating oil or grease passes from one recess to another through the apertures described. In determining the particular kind of lubricating oil or grease to be used, care should be exercised to select that kind which will flow from recess to recess when displaced by the downward or upward movement ofthe control shaft 5 at the speed at which it is desired the control shaft should move downwardly or upwardly. Oils whose viscosity is not affected within a wide temperature range will be preferable.

When the control shaft 5' Ihas moved downwardly to a point where the shoulder 17 rests upon the shoulder of the casting 4,' as illustrated in Fig. 3, the drill bit will proceed no further, and since the bit is not drilling, it will spin, causing the engine and rotary table to speed up, thus notifying the driller that it is then necessary to lower the drill pipe carried by the rotary table by means of the control hoist, a sufficient distance to again place the shoulder 17 against -the shoulder on the coupling 3, after which the drilling may proceed as heretofore described.

During the operation of lowering the drill pipe 1 by the control hoist a sutiicient distance to again place the shoulder 17 against the shoulder on the coupling 3, the control shaft" 5 will be again in its uppermost position, the oil being displaced during this movement in the reverse direction to the flow thereof previously despribed.

It will/be noted that shoulders on the shafts 5 andQl must displace oil during their movement upward or downward, which oil must be forced through the apertures provided between the different recesses. It is this action which furnishes the means whereby a sudden drop of the bit is prevented in case it strikes an opening or very soft formation.

I have illustrated the groove 16 as being spirally arranged on the shaft 5. It is obvious that I do not wish to limit the invention to a spiral groove, as the groove may be straight and disposed longitudinally of the shaft or it may take any other desired form. It should be understood further that I do not wish to limit the invention to a rib 15 and complemental groove 16 as the means for imparting rotary movement to the shaft 5', as may use a gear or other suitable means.

It is to be understood further that the shafts 5 and 24 may be made integral as a single shaft. One of the reasons why I have illustrated the hollow control shaft in two sections is to simplify manufacturing. It is vobvious that it would be easier to cut the groove in a short shaft than a long one. In

using one shaft, it is only necessary to ,pro-- vide it with shoulders.

I am aware that there are several expensive Well drilling bit controls on the market, and some are placed at the surface of the ground,

but `I have constructed a control which can be placed at most any depth below the surface of the ound and be operated without any mechanism at the surface other than raising or lowering the drill pipe at the end of a drill run to put the control shaft into position for another run. v

From the foregoing it will be obvious that I havedevised a rotary well drilling bit control` adapted to be placed at any epth below the surface of the ground as a part of the drill pipe transmitting rotary movement and power to drive the drill bit, and attached and so arranged in combination with the drill pipe leading to the rotary table at the .surface of the ground that the drill pipe control carried within the rotary well drilling bit control in said casing, means carried by said coupling v for driving said shaft in timed relation with said casing comprising a lu upon said coupling which is slidably positioned ywithin a substantially longitudinal groove in said hollow shaft, and means associated with said hollow shaft for limiting longitudinal motion of said shaft with respect to said casing, a liquid-tight plunger carried at the top of said shaft within said casing on one side of said coupling, a liquid-tight gland carried at the lower end of said casing upon the opposite side of said coupling, the space within said casing between said plunger and said gland adapted to carry a liquid to retard movement of said shaft with respect to said casing.

In testimony whereof I aiiix my signature.

JAN H. HOLLESTELLE.

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